Need reply to technical pressure drop question
We have a 23 year old home heat/cooling system. A plumber noticed our 20x25 2 inch filters and asked if they were rated for pressure drop since these older systems can be damaged with the wrong pressure rating. I have emailed FilterBuy several times with the pressure drop request but they never reply. So now I have a bunch of filters that I can't use until I can verify they won't damage my older equipment and cause flow failures. The filters themselves look and feel solid but I need the pressure drop info to safely use them and FilterBuy won't respond. Is a 1 inch lower drop? or will a 4 inch (because it has more surface area) be safer for pressure drop - I don't know and I really like FilterBuy filters construction but I really need an answer on this technical question befor I use them again.